The present invention relates to a circular knitting machine and, more particularly, to a circular knitting machine comprising a machine frame, a supporting ring mounted on the frame, a needle carrier supported on the supporting ring and having a needle carrier axis and upper and lower edge, a carrier shaft mounted in the frame coaxial to the axis, a component mounted on a lower end of the carrier shaft and a device for adjusting the relative position of the needle carrier and the component in the direction of the needle carrier axis so that the needle carrier can be disassembled or assembled by motions substantially perpendicular to the needle carrier axis as required.
Circular knitting machines with exchangeable needle cylinders have been known for a comparatively long time in the art, for example as described in German Patent 177 577.
In as much as the circular knitting machine has only one needle cylinder, its assembly and disassembly is comparatively easy. Besides assembly and disassembly this serves both repair and maintenance purposes as well as the purpose of operating the same knitting machine with needle cylinders of different gange and/or different diameter. Since the space above the needle cylinder is largely free, the needle cylinder and, if necessary the associated supporting ring needs to be lifted out or removed and inserted only from above the machine frame.
In contrast the assembly and disassembly of needle cylinders from above is not possible without further ado, when the circular knitting machine also has a component arranged above the needle cylinder, e.g. a dial or a yarn changing device, since then a removal of a component of this type would require the almost complete disassembly of the entire circular knitting machines For this case a device has already been provided and disclosed in European Patents EP 0 413 608 A1 and EP 0 436 313 A1, by means of which the relative position of the needle cylinder and the component above it is adjustable in a direction of the needle cylinder axis so that the needle cylinder can be disassembled or assembled by movements in a direction extending perpendicular to the needle cylinder axis, and indeed with or without the above-named component as desired. The device contains means by which the component can be moved upward far enough from the needle cylinder so that assembly or disassembly of the needle cylinder can occur from the side. The means for raising the above-mentioned component comprises, e.g., a conventionally present device for adjustment of the loop size by axial relative shifting of the component, especially when it is a dial.
A problem with this type of circular knitting machine which has not been solved up to now is that the assembly and disassembly of the needle cylinder itself is not easily possible even if the component is raised or lifted. A reason for this is that the needle cylinder is arranged with its lower edge generally in a recess in the cylinder ring and/or is provided with additional centering means which require a considerable lifting of the needle cylinder in disassembly and a corresponding lowering during assembly of the needle cylinder. These motions must be performed manually by operating persons handling the structural changes. Assembly and disassembly steps are then particularly difficult when the needle cylinder still is burdened by a component on it, e.g. a dial.